Place chicken, tomatoes, enchilada sauce, onion, green chiles, and garlic into a slow cooker. Pour in water and chicken broth, and season with cumin, chili powder, salt, pepper, and bay leaf. Stir in corn and cilantro. Cover, and cook on Low setting for 6 to 8 hours or on High setting for 3 to 4 hours. Preheat oven to 400. Lightly brush both sides of tortillas with oil. Cut tortillas into strips, then spread on a baking sheet. Bake for 10 to 15 minutes. To serve, sprinkle tortilla strips over soup.